<template>
  <div>
    <mark>生命周期</mark>
    <button @click="handleSwitch">切换</button>
    <Son v-if="is" :abc="abc" @getChange="getChange"></Son>
    <br /><br />
    <!-- 轮播 -->
    <el-carousel :interval="4000" type="card" height="200px">
      <el-carousel-item v-for="item in 6" :key="item">
        <h3 class="medium">{{ item }}</h3>
      </el-carousel-item>
    </el-carousel>
  </div>
</template>

<script>
import Son from "./Son";
export default {
  data() {
    return {
      is: true,
      abc: "来自父级的数据",
    };
  },
  methods: {
    getChange(value) {
      this.abc = value;
    },
    handleSwitch() {
      // 初级程序员--小白刚入门
      // if (this.is) {
      //   this.is = false
      // } else {
      //   this.is = true;
      // }

      // 三木运算符 入门一年
      // this.is = this.is ? false : true

      // 老手
      this.is = !this.is;
    },
  },
  components: { Son },
};
</script>

<style>
.el-carousel__item h3 {
  color: #475669;
  font-size: 14px;
  opacity: 0.75;
  line-height: 200px;
  margin: 0;
}

.el-carousel__item:nth-child(2n) {
  background-color: #99a9bf;
}

.el-carousel__item:nth-child(2n + 1) {
  background-color: #d3dce6;
}
</style>
